1. Technical Field
The present invention relates to a lighting device which is mounted on a vehicle.
2. Related Art
In this kind of lighting device, a lamp unit is disposed in a lamp chamber which is formed by a housing and a translucent member. In the lamp unit, a light source is fixed to a heat sink. The light emitted from the light source is guided in a predetermined direction by an optical system which includes a reflector, a projection lens, or the like and illuminates a predetermined region through the translucent member.
When the lamp unit is disposed in the lamp chamber, a configuration in which the lamp unit is attached from the outside of the housing has been known (for example, see JP-A-2012-164428). An opening is formed through a wall which forms the housing, and the lamp unit is introduced from a side, in which the projection lens is provided, into the housing through the opening. A portion of the heat sink closes the opening from the outside of the housing.
In the case of the configuration in which the lamp unit is attached from the outside of the housing, fixation portions, in which parts fixing the heat sink to the housing are disposed, should be disposed around the opening which is formed in the housing. Accordingly, an increase in the size of the portion of the heat sink closing the opening is unavoidable. Moreover, in order to cover a fixing part which is exposed into the housing, a shape of an extension which is disposed in the lamp chamber is limited.